Field of the Invention
Exemplary embodiments of the inventive concept relate to a thin film transistor substrate capable of improving reliability, a liquid crystal display panel having the thin film transistor substrate, and a method of manufacturing the thin film transistor substrate.
Description of the Related Art
Generally, a liquid crystal display apparatus has a liquid crystal layer arranged between an array substrate and an opposite substrate, the liquid crystal layer including a plurality of liquid crystals. The liquid crystal display apparatus also has a light source, such as a backlight unit, to apply light to a liquid crystal display panel. Light from the light source is applied to the liquid crystal display panel that includes the array substrate, the opposite substrate and the liquid crystal layer. The liquid crystal display apparatus displays an image by controlling amount of light that passes the substrates according to an alignment of liquid crystals.
The array substrate may include a plurality of pixels, a plurality of switching elements, such as thin film transistors, that are electrically connected to the pixels, and gate and data lines electrically connected to the switching elements. Each of the thin film transistors may have a bottom gate structure. The thin film transistors of the bottom gate structure may be formed by patterning a metal layer using a photoresist pattern.
For example, in a four mask manufacturing process having four different mask processes, a photoresist pattern is partially removed by ashing process, so that source and drain electrode of the thin film transistors may be formed. However, during the ashing process of the photoresist pattern, an under-cut may occur at ends of the photoresist pattern due to an over process, and the under-cut may influence the patterning and the final design of the thin film transistors.